Lewis & Short

ĕpogdŏŏs, -ŏus, acc. ŏŏn or ŏum, adj., = ἐπόγδοος, containing a whole and an eighth: numerus, the proportion of nine to eight, Macr. Somn. Scip. 2, 1, 14; Mart. Cap. 2, § 109; Fulg. Myth. 3, 9.